Human-powered movement through water has always been a challenge. Because of constraints presented by body characteristics which are designed for motion on land, humans can only envy the smooth and graceful propulsion methods of aquatic creatures. Through the use of swimming aids such as attachable fins and paddles, men have attempted to increase ease and speed of motion through water. These efforts to improve efficiency in human-powered swimming have had only limited success.
Devices such as described in prior art U.S. Pat. Nos. 4,289,487, 4,867,720, and 5,421,758 are complicated and tend to need unnatural or difficult actions by the swimmer. Improving fin design, or utilizing paddles such as in prior art U.S. Pat. Nos. 3,987,509, 4,541,810, 5,348,503, 5,649,845, and 5,820,428 are only moderately successful in facilitating human motion through water. By increasing the surface area which reacts with water, the effort of the swimmer becomes more effective. This is an underlying principal presented by virtually all of the prior art.
Extending and Positioning of swimming aids such as attachable fins may be as important as their design and size. Prior art U.S. Pat. Nos. 5,906,525 and 5,421,758 somewhat describe extension and location of the surface area of a fin out from the foot, but utilization of this leverage-gaining characteristic is minor compared to that leverage gained by the instant invention.
Constraints in the human anatomy, beside an obvious lack of surface area which reacts with water, include inappropriate leverage and a generally incompatible hinging of many body joints for necessary movements in water. The knee, for example, is hinged substantially in a posterior/anterior manner, making side to side motion uncomfortable and difficult. A design employing such an unnatural movement for tailfin power is shown in prior art U.S. Pat. No. 5,348,503. The human, therefore, is limited in options as far as the design for viable operation of assisting devices for swimming.
The structure of the entire human body lends itself best to producing forces toward the front and back, rather than side to side. An aid to propulsion is best designed in a compatible orientation. Common swimming gear, such as foot fins and paddles enhance the effects of the natural action of kicking and arm rotation for water movement. Although design features for these items improve results, they have shown to have only limited effectiveness. The instant invention also uses the natural movement associated with humans to provide the force necessary for water movement, but in a more effective and efficient manner.
A device which mimics the design of aquatic creatures and effectively merges such design with the limitations of the human anatomy is presented herein. As described in the referenced 1995 Scientific American article xe2x80x9cAn Efficient Swimming Machinexe2x80x9d, many fishes and sea mammals are propel efficiently utilizing primarily their singular tailfins. Referenced prior art U.S. Pat. No. 5,401,196 by the same author teaches the utilization of such tailfins for propulsion, and explains advantages to be gained. Vortices produced by tailfin strokes produce interactions with subsequent strokes and thereby increase efficiency to a degree not yet achieved by human water propulsion devices. Evolution has shown this principle to be effective, evidenced by the multitude of organisms using tailfins. Although many fishes stroke their tailfin horizontally, others are successful stroking in a vertical manner. Sea mammals such as whales and dolphins, believed to have evolved from land animals, utilize this vertical stroking motion, probably because it conforms most directly to their land-based anatomy. Since vertical stroking seems to present no disadvantage to survival, these animals have not needed to evolve further to a horizontal stroking orientation.
Because man is a land animal, it follows that the human anatomy conforms best to the principles of movement utilized in water by whales and dolphins. The instant device provides a marriage of the structure of the human body with these principles. Since singular tailfin action is extremely efficient, it is the underlying principal of the invention, and human legs provide the strength for thrust. Because people are designed for walking and running, leg action on humans is stronger than for other body parts, and the legs can last for longer periods under physical stress. Leg strength, along with lever action and restoring resilience of the device, provide a new and effective method for aiding in efficient human-powered movement through water.
By utilizing principles of leverage in conjunction with a design which matches well with that of the human anatomy, this device aids in increasing the speed, ease and efficiency by which a person may move both above and below the surface of the water. It is of simple design, and may be constructed with materials available at present. An elastic elongate structure which provides a springboard restoring force, unprecedented in the prior art, differentiates the instant invention from prior art. A flexible structure is an important component in mimicking the flapping action of aquatic creatures, which use a resilient backbone to accomplish the same feat. This unique feature not only provides structure, but is essential to the operation. It may be composed of an elastic substance such as metallic spring, plastic, or composite material available today. Elasticity supplies a restoring recoil force when distorted, thereby facilitating the user""s subsequent tailfin stroke. Successive strokes are therefore more easily and more quickly performed. Prior art U.S. Pat. No. 4,867,720 teaches a device which is firmly attached to the legs and supplies resilience to assist a swimmer in normal swimming activity. This prior art does not have many of the advantages of the instant device, in that it is merely an attachment to the legs, affects the efficiency of the swimmer only in the leg area, cannot be utilized on a singular fin without presenting unobvious redesign problems for comfort and efficiency, and does not address the novel combination presented in the instant invention. The elasticity presented in this prior art is confined strictly to the knee area and therefore affords little mechanical advantage compared with the instant invention. Because the hips are pivotable, the elastic supplement described is not secured at an end to form a springboard, and effectiveness is severely curtailed.
By longitudinal adjustment of forward and rearward leg levering means, a comfortable and efficient match for virtually all human dimensions may be attained. The longitudinal positioning of the tailfin is another adjustment which affects the performance of the assemblage. By extending the fin, the lever action of the device is altered, varying performance. Therefore, by making the components of the invention longitudinally adjustable, an ideal configuration for a particular user may be acquired.
Many variations to the design of the invention are possible, depending upon the needs of the swimmer. For underwater diving purposes, the buoyancy of the device may ideally be neutral with respect to water. Adjustable buoyancy is a possibility for certain purposes and a variety of methods could be used. Cushioning may be advantageous at locations throughout the device in order to prevent abrasion to the swimmer caused by repetitive motions and contact with parts of the device. These protective cushions also provide buoyancy if needed, using materials such as styrofoam to accomplish both tasks.
The independent nature of the device is a major variation from the prior art. By simply straddling the device in a longitudinal manner and inserting legs and feet into the appropriate leverage elements, the user is instantaneously prepared to accelerate. There is no need for strapping, tying, or binding the invention in any way, as opposed to requirements presented in virtually all prior art. In addition, separation of the swimmer from the device is accomplished simply by reversing the process, allowing for quickness and safety. Essentially, the user may swim into or away from the invention when desired.
Obviously, the novel nature of the instant invention opens a variety of possibilities for its design and use.
This invention relates to devices which improve human motion through water. The object of this invention is to provide a simple, efficient and fast method for human-powered movement through water. It may be used both on the surface and under water for recreational or working purposes. A bendable elongate member having a large fin at a rearward end is longitudinally mounted by a swimmer whose legs are thereafter inserted into at least two communicating leverage elements. The legs and device therefore substantially form a class III type lever to act upon the fin, while the torso stabilizes the forward portion of the flexible elongate member to effectively produce a springboard. The swimmer employs a repetitive pumping motion with his/her legs thereby displacing the fin successively upward and downward and causing forward motion in a manner similar to whales and other aquatic creatures. Recoil force stored in the flexed elongate member substantially form a springboard action and aid the swimmer in sequential strokes. Adequate flotation and padding are applied as necessary for comfort, control, and mounting purposes.